A5078217920- Laser-Plasma Interactions and Diagnostics
- Laser-Matter Interactions and Applications
- Laser-induced spectroscopy and plasma
- Particle Accelerators and Free-Electron Lasers
- Laser Design and Applications
- Pulsed Power Technology Applications
- Particle accelerators and beam dynamics
- Advanced Fiber Laser Technologies
- Plasma Diagnostics and Applications
- Photonic Crystal and Fiber Optics
- Advanced Surface Polishing Techniques
- Advanced Optical Sensing Technologies
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Renewable energy and sustainable power systems
- Advanced X-ray Imaging Techniques
- Particle Detector Development and Performance
- Atomic and Molecular Physics
- Radiation Therapy and Dosimetry
- Optical Systems and Laser Technology
- Solid State Laser Technologies
- Advanced Data Compression Techniques
- Image Processing Techniques and Applications
- Engine and Fuel Emissions
- Image and Signal Denoising Methods
University of Oxford
2014-2024
Science Oxford
2012
Institute of Agrophysics, Polish Academy of Sciences
2007
University of Warsaw
1987
Heidelberg University
1984
Max Planck Institute for Nuclear Physics
1984
We present experiments and numerical simulations which demonstrate that fully ionized, low-density plasma channels could be formed by hydrodynamic expansion of columns produced optical field ionization. Simulations the in hydrogen an axicon lens show generation 200 mm long with axial densities order ${n}_{\mathrm{e}}(0)=1\ifmmode\times\else\texttimes\fi{}{10}^{17}\phantom{\rule{0.16em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$ lowest-order modes spot size...
We demonstrate experimentally the resonant excitation of plasma waves by trains laser pulses. also take an important first step to achieving energy recovery accelerator showing that unused wakefield can be removed out-of-resonance trailing pulse. The measured wakefields are found in excellent agreement with analytical and numerical models linear regime. Our results indicate a promising direction for highly controlled, GeV-scale laser-plasma accelerators operating at multi-kilohertz...
Laser-driven plasma accelerators can generate accelerating gradients three orders of magnitude larger than radio-frequency and have achieved beam energies above 1 GeV in centimetre long stages. However, the pulse repetition rate wall-plug efficiency laser is limited by driving to less approximately Hz 0.1% respectively. Here we investigate prospects for exciting wave with trains low-energy pulses rather a single high-energy pulse. Resonantly wakefield this way would enable use different...
We demonstrate through experiments and numerical simulations that low-density, low-loss, meter-scale plasma channels can be generated by employing a conditioning laser pulse to ionize the neutral gas collar surrounding hydrodynamic optical-field-ionized (HOFI) channel. use particle-in-cell show leading edge of ionizes generate deep, low-loss channel which guides bulk itself as well any subsequently injected pulses. In proof-of-principle experiments, we conditioned HOFI (CHOFI) waveguides...
Hydrodynamic optically-field-ionized (HOFI) plasma channels up to 100 mm long are investigated. Optical guiding is demonstrated of laser pulses with a peak input intensity 6×1017 W cm−2 through on-axis densities measured interferometrically be as low ne0=(1.0±0.3)×1017 cm−3. Guiding also observed at lower axial densities, which inferred from magneto-hydrodynamic simulations approximately 7×1016 Measurements the power attenuation lengths shown in good agreement those calculated transverse...
We describe a simple scheme, truncated-channel injection, to inject electrons directly into the wakefield driven by high-intensity laser pulse guided in an all-optical plasma channel. use this approach generate dark-current-free 1.2 GeV, 4.5% relative energy spread electron bunches with 120 TW pulses 110 mm-long hydrodynamic optical-field-ionized Our experiments and particle-in-cell simulations show that high-quality were only obtained when drive was closely aligned channel axis, focused...
This document provides detailed information on the status of Advanced and Novel Accelerators techniques describes steps that need to be envisaged for their implementation in future accelerators, particular high energy physics applications. It complements overview prepared update European Strategy particle physics, a description field. The scientific priorities community are described each technique acceleration able achieve accelerating gradient GeV~range or above. ALEGRO working group...
Abstract The intrinsic constraints in the amplitude of accelerating fields sustainable by radio-frequency accelerators demand for pursuit alternative and more compact acceleration schemes. Among these, plasma-based are arguably most promising, thanks to high-accelerating they can sustain, greatly exceeding GeV/m. While electrons is now sufficiently mature systematic studies this direction, positron still at its infancy, with limited projects currently undergoing provide a viable test...
We demonstrate experimentally that hydrodynamic optical-field-ionized (HOFI) plasma channels can be generated at kHz-scale pulse repetition rates, in a static gas cell and for an extended period. Using pump-probe arrangement, we show via transverse interferometry the properties of two HOFI \SI{1}{ms} apart are essentially same. mean rate \SI{0.4}{kHz} period 6.5 hours without degradation channel properties, determine fluctuations key optical parameters this Our results suggest conditioned...
We demonstrate optical guiding of high-intensity laser pulses in long, low-density hydrodynamic optical-field-ionized (HOFI) plasma channels. An axicon lens is used to generate HOFI channels with on-axis electron densities as low ${n}_{e}(0)=1.5\ifmmode\times\else\texttimes\fi{}{10}^{17}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}3}$ and matched spot sizes the range $20\text{ }\ensuremath{\mu}\mathrm{m}\ensuremath{\lesssim}{W}_{M}\ensuremath{\lesssim}40\text{ }\ensuremath{\mu}\mathrm{m}$....
We investigate the accelerator stage of a plasma-modulated plasma (P-MoPA) [Jakobsson et al., Phys. Rev. Lett. 127, 184801 (2021)0031-900710.1103/PhysRevLett.127.184801] using both paraxial wave equation and particle-in-cell (PIC) simulations. show that adjusting laser parameters modulator P-MoPA allows temporal profile pulses within pulse train to be controlled, which in turn wake amplitude as much 72% larger than generated by beat-wave with same total drive energy. Our analysis shows...
In multi-pulse laser wakefield acceleration (MP-LWFA) a plasma wave is driven by train of low-energy pulses separated the period, an approach which offers route to driving accelerators with high efficiency and at pulse repetition rates using emerging technologies such as fibre thin-disk lasers. Whilst these are in development, proof-of-principle tests MP-LWFA require be generated from single, high-energy ultrafast pulse. Here we demonstrate generation trains up 7 separations range 150–170 fs...
We describe a new approach for driving GeV-scale plasma accelerators with long laser pulses. show that the temporal phase of long, high-energy pulse can be modulated periodically by copropagating it low-amplitude wave driven short, low-energy seed pulse. Compression driver dispersive optic generates train short pulses suitable resonantly accelerator. Modulation occurs via well-controlled linear processes, as confirmed good agreement between particle-in-cell (PIC) simulations and an analytic...
In recent years, hydrodynamic optical-field-ionized (HOFI) channels have emerged as a promising technique to create laser waveguides suitable for guiding tightly focused pulses in plasma, needed laser-plasma accelerators. While experimental advances HOFI continue be made, the underlying mechanisms and roles of main parameters remain largely unexplored. this paper, we propose start-to-end simulation pipeline channel formation resulting use it explore physics tunability channels. This approach...
A train of laser pulses guided by a 100-mm-long, all-optical plasma channel resonantly excites large amplitude wave. Pulse trains similar kind could be generated joule-scale thin-disk lasers, offering route to driving GeV-scale accelerators at kilohertz pulse repetition rates.
A laser-wire transverse electron beam size measurement system has been constructed and operated at the Accelerator Test Facility (ATF) extraction line KEK. The construction of is described in detail along with environment ATF related to laser wire. special set optics was developed generate an approximately $1\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ vertical focus location. results our operation are presented, where a minimum rms $4.8\ifmmode\pm\else\textpm\fi{}0.3\text{ measured, smaller...
We explore the regime of operation modulator stage a recently proposed laser-plasma accelerator scheme [Phys. Rev. Lett. 127, 184801 (2021)0031-900710.1103/PhysRevLett.127.184801], dubbed plasma-modulated plasma (P-MoPA). The P-MoPA offers potential route to high-repetition-rate, GeV-scale accelerators driven by picosecond-duration laser pulses from, for example, kilohertz thin-disk lasers. first is in which long, high-energy "drive" pulse spectrally modulated copropagating channel with...
A laserwire transverse electron beam size measurement system has been developed and operated at the Accelerator Test Facility 2 High Energy Research Organization, Japan (KEK). Special optics were to create an approximately $1\ifmmode\times\else\texttimes\fi{}100\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ ($\text{vertical}\ifmmode\times\else\texttimes\fi{}\text{horizontal}$) location, which was profiled using 150 mJ, 71 ps laser pulses with a wavelength of 532 nm. The precise characterization...
Particle size distribution affects many physical soil properties and processes taking place in soil. There are methods to determine the particle distribution. The most frequently used sieve, sieve-pipette sedimentation methods. Technological progress electronics permitted a wide use of new measurement soil, e.g. laser diffraction method. A comparison obtained with universally areometer method (Cassagrande, modified by Prószynski) results from for material received grey-brown podzolic is...
We investigate the growth of ion density perturbations in large-amplitude linear laser wakefields via two-dimensional particle-in-cell simulations. Growth rates and wave numbers are found to be consistent with a longitudinal strong-field modulational instability. examine transverse dependence instability for Gaussian wakefield envelope show that can maximized off axis. On-axis decrease increasing mass or electron temperature. These results close agreement dispersion relation Langmuir an...
The ATF extraction line laser-wire (LW) aims to achieve a micron-scale laser spot size and verify that micron- scale beam profile measurements can be performed at the International linear collider delivery system. Recent upgrades LW system are presented together with recent results including first use of as diagnostic tool.
We present the development of a high power fiber laser system to investigate its suitability for use in transverse electron beam profile monitor, i.e., laserwire. A capable producing individual pulses up $165.8\ifmmode\pm\else\textpm\fi{}0.4\text{ }\text{ }\ensuremath{\mu}\mathrm{J}$ at 1036 nm with full width half maximum $1.92\ifmmode\pm\else\textpm\fi{}0.12\text{ }\mathrm{ps}$ 6.49 MHz is demonstrated using master oscillator amplifier design final amplification stage rod-type photonic...